Levi is the son of Kushel Ackerman, who worked in an underground city brothel and had an unknown client. Kenny, who is Kushel's older brother, convinced the woman to abandon the child. However, she did not listen and decided to raise her son herself. When Kenny found himself in the ranks of the police, he found his sister, wanting to help her. However, it was too late - Kushel died as a result of the disease. There he found Levi, emaciated and dying of hunger, sitting in front of his mother's bed. Showing rare compassion, Kenny takes custody of Levi and raises him for several years, teaching him what he knows about fighting and survival. Levi also learned to use his inner strength, which he possessed as a member of the Ackerman clan.

Levi has short, straight, black hair, parted on the right side with roughly cut ends; narrow, scary, dull gray-blue eyes with dark circles under them due to lack of sleep and a deceptively youthful face. He is short in stature, but has well-developed muscles due to his frequent use of the UPM. As a rule, Levi either frowns or expresses nothing, which, coupled with his extremely calm demeanor, often makes it difficult for others to understand what he is thinking. He is most often seen in his Survey Corps uniform with a light gray button-up shirt underneath and his signature frill. When going on expeditions beyond the walls, he also wears a green cloak with a hood and the Survey Corps insignia on the back. When Levi was forced to relinquish his duties as captain due to injury, he wore a black suit, a simple white shirt, black patent leather shoes and the same white frill.